Ribbon spool having plastic discs and a metal core

ABSTRACT

A ribbon spool for typewriters, accounting machines, business machines and the like for mounting on a spool pin comprises a pair of plastic discs. A metallic spool core is bent into cylindrical shape and secures the discs so as to be concentric and parallel spaced-apart. Each disc includes a plurality of slots disposed therethrough. One side of each disc includes an injection molded channel having an integrally formed circular collar extending therefrom for engaging the spool core. The channels further include a plurality of reinforcing ribs radially disposed from the channel and extending to the collar periphery. The plastic discs have longitudinal recesses placed on their face opposite the channel for receiving a plurality of bending lugs extending from and along the spool axis. By utilizing a metallic spool core a pointed catch may be employed for fastening the ribbon to the spool.

States atent n91 Bille Sept. 24, 1974 RIBBON SPOOL HAVING PLASTIC DISCS AND A METAL CORE [73] Assignee: Regentrop & Bernard KG,

Wuppertal-Vohwinkel, Germany 22] Filed: Apr. 11,1973

[21] Appl.No.:350,275

[30] Foreign Application Priority Data 2,853,175 9/1958 Regentrop et al. 197/175 2,873,839 2/1959 Bishop 3,042,180 7/1962 Bishop 197/175 Primary Examiner-Ernest T. Wright, Jr. Attorney, Agent, or Firm-Allison C. Collard [5 7] ABSTRACT A ribbon spool for typewriters, accounting machines, business machines and the like for mounting on a spool pin comprises a pair of plastic discs. A metallic spool core is bent into cylindrical shape and secures the discs so as to be concentric and parallel spacedapart. Each disc includes a plurality of slots disposed therethrough. One side of each disc includes an injection molded channel having an integrally formed circular collar extending therefrom for engaging the spool core. The channels further include a plurality of reinforcing ribs radially disposedfrom the channel and extending to the collar periphery. The plastic discs have longitudinal recesses placed on their face opposite the channel for receiving a plurality of bending lugs extending from and along the spool axis, By utiliz ing a metallic spool core a pointed catch may be employed for fastening the ribbon to the spool.

4 Claims, SDrawing Figures This invention relates to a spool for typewriters, accounting machines, bookkeeping machines and the like. More particularly, this invention relates to a spool having two side disks and including a spool core with a pointed catch for attaching the ribbon.

Spools of the prior art generally consist of two circular side discs kept apart by a cylindrical hollow core. A ribbon is wound onto the core. A cylindrical guide is provided in the spool core for mounting the spool onto the spool pin of a machine. These guides frequently have an inserting channel. Furthermore, catch openings are included in the side disks. In standardized spools these openings comprise 120 offset openings so that one catch pin on the machine engages the ribbon transport. A pointed catch used for attaching the ribbon to the spool is mounted on the spool core. The catch is stamped so as to protrude outwardly from the spool core.

The spools of the above mentioned type are usually fabricated from metal. The side disks as well as the spool core are stamped from sheet metal and, without machining or cutting, are formed and assembled. These spools are undesirable owing to their high costs. Furthermore, a serious disadvantage of the prior art spools is their weight. This causes higher shipping costs, which is particularly undesirable when spools are exported overseas.

Accordingly, it has been suggested to fabricate the above-described spools from plastic by injection molding. However, the expected results have not materialized. Obviously, the manufacturing and shipping costs of plastic spools would be relatively lower than for spools consisting of metal. However, this advantage is offset by other problems. For example, the catch used in attaching the ribbon to the spool core cannot be bent, as is possible with metal catches. Thus, automatic winding of the ribbons onto the spools is not possible. Consequently, when winding the ribbon onto the spool, the ribbon must be manually attached to the catch thereby increasing labor costs. Another problem is that the ribbon does not evenly move in the machine.

In another prior art spool the side disks and the core consist of plastic material and have the metal catch used in attaching the ribbon to the spool bonded to the plastic core. However, these spools are expensive to manufacture and do not permit even movement of the ribbon in the machine or typewriter.

It is therefore an object of the present invention to provide a ribbon spool which overcomes the abovementioned disadvantages. v

It is another object of the present'invention to provide a spool that can be inexpensively manufactured, that is light weight and that assures a smooth movement of the ribbon in the machine.

Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawing which discloses the embodiments of the present invention. It should be understood however, that the drawing is designed for the purpose of illustration only and not as a definition of the limits of the invention to which reference should be made to the appended claims.

In the drawing, wherein similar reference characters denote similar elements throughout the several views:

FIG. 1 is a side view of the inner face of a spool side disk according to the present invention;

FIG. 2 is a vertical section through an inventive spool;

FIG. 3 is an enlarged partial view of FIG. 2;

FIG. 4 is an exploded perspective of the inventive spool; and

FIG. 5 is a perspective view of the fully assembled spool of FIG. 4.

Referring now to FIGS. 1-5, a disc 6 comprises a circular flat injection molded plastic disc having a central opening 61. Opening 61 is defined by channel 62. The inner diameter of channel 62 corresponds to the diameter of central opening 61. Reinforcing ribs 67 support guide channel 62. An annular or radial collar 63 is provided on disc 6 and is concentric with guide channel 62. The outside diameter of collar 63 equals the inner diameter of a metal spool core 7 as shown.

Spool discs 6 include radial openings 64 and slots 65 arranged in an abutment face of annular collar 63 as seenin FIG. 3. The openings 64 along with guide channel 62 serve to selectively receive a transport pin (not shown) of the typing apparatus. Slots 65 are penetrated by a plurality of fastening tongues 71 integrally formed with metal spool core 7. On the outward side of each disc 6, a plurality of material recesses 66 are provided. Channel 62 and each recess 66 includes a slot 65 for receiving a fastening tongue or lug 71 of spool core 7. When the spool body is assembled, as seen in FIGS. 3 and 5, the fastening tongues 71 bend within slot 65 so as to reside within recesses 66.

Metal spool core 7 is stamped from sheet metal and is subsequently formed by a tool (not shown) to the configuration shown in FIG. 4. Metal spool core 7 includes a pointed catch 72 to which attaches one end of a ribbon (not shown). After the ribbon (not shown) is attached, the pointed end of the catch 72, which initially is in a tangential direction is bent inwardly. A recess 73 is provided in the edge portion of the spool core 7 permitting catch 72 to bend as described. Recess 73 is disposed opposite the pointed end of catch 72 as shown.

While only a single embodiment of the present invention has been shown and described it will be apparent to those skilled in the art that many changes and modifications may be made thereto without departing from the spirit and scope of the invention..

What is claimed is: v y

' 1. A ribbon spool for typewriters, accounting machines, business machines and the like for mounting on a spool pin comprising:

a pair of parallel spaced-apart plastic discs each hav-v ing inner and outer surfaces and a projecting cylindrical guide channel defining a central opening, the guide channels being directed toward each other;

a radial collar surrounding each guide channel formed on the inner disc surfaces facing each other;

radial reinforcing ribs joining each of said guide channels to each radial collar;

radial spaced-apart slots formed around the radial collar through each disc and tongue receiving re- 2. The ribbon spool as recited in claim 1 wherein said radial collar includes radially spaced apart apertures disposed between said reinforcing ribs.

3. The ribbon spool as recited in claim 1 wherein said metal spool core includes a catch recess formed opposite the pointed catch.

4. The ribbon spool as recited in claim 1 wherein the cylindrical guide channels of each disc are held in spaced apart relationship by said spool core. 

1. A ribbon spool for typewriters, accounting machines, business machines and the like for mounting on a spool pin comprising: a pair of parallel spaced-apart plastic discs each having inner and outer surfaces and a projecting cylindrical guide channel defining a central opening, the guide channels being directed toward each other; a radial collar surrounding each guide channel formed on the inner disc surfaces facing each other; radial reinforcing ribs joining each of said guide channels to each radial collar; radial spaced-apart slots formed around the radial collar through each disc and tongue receiving recesses extending from each slot toward The central opening on the outer surface of each disc; a metal spool core substantially cylindrical in shape having a plurality of radially spaced-apart fastening tongues extending from each end thereof and extending through the radial slots of said discs and bent over into the receiving recesses on the outer surfaces of the discs, so as to secure the discs in coaxial alignment; and a pointed catch formed on said spool core for engagement with a ribbon.
 2. The ribbon spool as recited in claim 1 wherein said radial collar includes radially spaced apart apertures disposed between said reinforcing ribs.
 3. The ribbon spool as recited in claim 1 wherein said metal spool core includes a catch recess formed opposite the pointed catch.
 4. The ribbon spool as recited in claim 1 wherein the cylindrical guide channels of each disc are held in spaced apart relationship by said spool core. 